The invention relates to a method for producing a multicolored surface on a ceramic element or glass by the drop-like application of differently colored primary ceramic process color inks containing a carrier fluid onto at least part of a surface of the ceramic element or glass, whereby mixed colors are produced by printing on top of one another at least two primary process color inks, and subsequently firing the applied ink drops, a printing ink system consisting of several differently colored, primary ceramic process color inks, from which mixed colors can be produced by printing on top of one another at least two primary ceramic process color inks, wherein each of the primary ceramic process color inks comprises at least one inorganic pigment, a frit, a dispersing agent and an in particular organic carrier fluid and a device for producing a multicolored surface on a ceramic element or glass by the drop-like application of variously colored, primary ceramic process color inks onto at least one portion of a surface of the ceramic element or glass, wherein mixed colors are produced by printing on top of one another at least two primary process color inks, comprising several delivery elements for the process color inks and a support device for depositing the ceramic element or glass during the application of the process color inks.
Particularly high demands are made on the decorative glass in facades in relation to sun radiation and durability. This has been solved in the past largely by using colored glass or by a screen printing method using ceramic inks.
Screen printing has the disadvantage that after the application of one color and before the application of the next color, resulting in a mixed color, the color applied first has to be completely dried (tempered) in a through oven, in order to be able to apply the next color without running. Screen printing also has the disadvantage that for each color and each decoration a separate screen has to be set up. In addition, screen printing inks have the disadvantage of being completely opaque and not transparent.
U.S. Pat. No. 6,336,723 B1 describes a method for producing glass substrates with patterns on a color base. In this case the desired pattern starting with a template, which is produced in any colors on any carrier and is prepared electronically by means of image processing, is printed by an inkjet printer with four colors onto the glass and the colors are then fired. The colors used for firing on glass at about 500° C. to 700° C. are suitable, conventional firing colors with inorganic pigments. The latter are diluted by a diluent to the extent that the application of color is possible with inkjet printers. After the printing and before the firing the glass discs are stored in a horizontal position until the color application has largely dried.